21725522 has 24 divisors (see below), whose sum is σ = 40827276. Its totient is φ = 8594208.

The previous prime is 21725519. The next prime is 21725533. The reversal of 21725522 is 22552712.

It can be written as a sum of positive squares in 2 ways, for example, as 20259001 + 1466521 = 4501^2 + 1211^2 .

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a junction number, because it is equal to n+sod(n) for n = 21725491 and 21725500.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7253 + ... + 9800.

Almost surely, 2^21725522 is an apocalyptic number.

21725522 is a deficient number, since it is larger than the sum of its proper divisors (19101754).

21725522 is a wasteful number, since it uses less digits than its factorization.

21725522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17082 (or 17075 counting only the distinct ones).

The product of its digits is 2800, while the sum is 26.

The square root of 21725522 is about 4661.0644706977. The cubic root of 21725522 is about 279.0337527627.

The spelling of 21725522 in words is "twenty-one million, seven hundred twenty-five thousand, five hundred twenty-two".